User Benjamin Steinberg

68 votes

Why aren't representations of monoids studied so much?

answered Jun 22, 2011 at 3:19

59 votes

Which mathematical definitions should be formalised in Lean?

answered Sep 21, 2018 at 15:11

45 votes

Results from abstract algebra which look wrong (but are true)

answered Jan 19, 2023 at 23:42

40 votes

What are the benefits of viewing a sheaf from the "espace étalé" perspective?

answered May 8, 2012 at 0:12

38 votes

Accepted

Is it decidable to check if an element has finite order or not?

answered Oct 5, 2016 at 16:31

37 votes

Changes forced by the pandemic

answered May 30, 2021 at 14:43

31 votes

Results from abstract algebra which look wrong (but are true)

answered Jan 19, 2023 at 23:41

31 votes

Why is the fundamental group of a compact Riemann surface not free ?

answered Apr 6, 2012 at 17:34

30 votes

Accepted

Number of irreducible representations of a finite group over a field of characteristic 0

answered Nov 4, 2018 at 12:36

29 votes

What recent programmes to alter highly-entrenched mathematical terminology have succeeded, and under what conditions do they tend to succeed or fail?

answered Jul 11, 2014 at 20:06

28 votes

Not especially famous, long-open problems which anyone can understand

answered Jun 22, 2012 at 21:28

27 votes

Accepted

Why do we associate a graph to a ring?

answered Oct 15, 2020 at 15:24

27 votes

Accepted

Is "almost-solvability" of Diophantine equations decidable?

answered Aug 2, 2021 at 11:52

25 votes

Accepted

How many category structures are possible on two sets?

answered Apr 29, 2021 at 13:18

25 votes

Publishing a bad paper?

answered Dec 19, 2012 at 20:05

24 votes

Results from abstract algebra which look wrong (but are true)

answered Jan 19, 2023 at 23:46

24 votes

Solving algebraic problems with topology

answered Jun 1, 2015 at 13:43

23 votes

Accepted

Are there any "simple" monoids with intermediate growth?

answered Mar 27, 2021 at 14:37

23 votes

Counterexamples in universal algebra

answered Jan 9, 2014 at 3:18

22 votes

Accepted

Shortest supersequence of all permutations of $n$ elements

answered May 6, 2014 at 14:28

22 votes

free group of finite rank can contain free groups of infinite rank as a subgroup

answered Sep 8, 2011 at 16:53

21 votes

Applications for p-Sylow subgroups theorem

answered Jun 23, 2011 at 3:11

21 votes

Old books still used

answered Dec 28, 2012 at 21:11

20 votes

Are there any computational problems in groups that are harder than P?

answered Jan 23, 2019 at 18:09

19 votes

Accepted

Does there exist an ordering-functor?

answered Nov 17, 2020 at 16:10

19 votes

Accepted

A ring for which the category of left and right modules are distinct

answered Nov 3, 2021 at 13:28

18 votes

Accepted

How many finitely-generated-by-elements-of-finite-order-groups are there?

answered Apr 16, 2021 at 1:31

18 votes

Accepted

Number of solutions to equations in finite groups

answered Feb 24, 2015 at 3:32

18 votes

Number of idempotent $n\times n$ matrices over $\mathbb{Z}/m\mathbb{Z}$?

answered Feb 13, 2013 at 21:52

18 votes

Accepted

Is it ever a good idea to use Keisler-Shelah to show elementary equivalence?

answered Feb 25, 2014 at 7:44

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558 Answers

Why aren't representations of monoids studied so much?

Which mathematical definitions should be formalised in Lean?

Results from abstract algebra which look wrong (but are true)

What are the benefits of viewing a sheaf from the "espace étalé" perspective?

Is it decidable to check if an element has finite order or not?

Changes forced by the pandemic

Results from abstract algebra which look wrong (but are true)

Why is the fundamental group of a compact Riemann surface not free ?

Number of irreducible representations of a finite group over a field of characteristic 0

What recent programmes to alter highly-entrenched mathematical terminology have succeeded, and under what conditions do they tend to succeed or fail?

Not especially famous, long-open problems which anyone can understand

Why do we associate a graph to a ring?

Is "almost-solvability" of Diophantine equations decidable?

How many category structures are possible on two sets?

Publishing a bad paper?

Results from abstract algebra which look wrong (but are true)

Solving algebraic problems with topology

Are there any "simple" monoids with intermediate growth?

Counterexamples in universal algebra

Shortest supersequence of all permutations of $n$ elements

free group of finite rank can contain free groups of infinite rank as a subgroup

Applications for p-Sylow subgroups theorem

Old books still used

Are there any computational problems in groups that are harder than P?

Does there exist an ordering-functor?

A ring for which the category of left and right modules are distinct

How many finitely-generated-by-elements-of-finite-order-groups are there?

Number of solutions to equations in finite groups

Number of idempotent $n\times n$ matrices over $\mathbb{Z}/m\mathbb{Z}$?

Is it ever a good idea to use Keisler-Shelah to show elementary equivalence?